void UpdateRootPage(IReadOnlyList <Page> stack)
{
Page first = stack.FirstOrDefault();
if (first == _currentRoot)
{
return;
}
if (Children.Count > 0)
{
var renderer = Children[0] as IVisualElementRenderer;
if (renderer != null)
{
Children.RemoveAt(0);
var page = renderer.Element as IPageController;
if (page != null)
{
page.IgnoresContainerArea = false;
}
if (!stack.Contains(renderer.Element))
{
Platform.SetRenderer(renderer.Element, null);
}
}
}
_currentRoot = first;
if (first == null)
{
return;
}
((IPageController)first).IgnoresContainerArea = true;
IVisualElementRenderer firstRenderer = Platform.GetRenderer(first);
if (firstRenderer == null)
{
firstRenderer = Platform.CreateRenderer(first);
Platform.SetRenderer(first, firstRenderer);
}
var uiElement = (UIElement)firstRenderer;
var platform = Element.Platform as Platform;
Canvas canvas = platform?.GetCanvas();
//We could be swapping the visible page,
//so let's make sure we remove it
if (canvas.Children.Contains(uiElement))
{
canvas.Children.Remove(uiElement);
}
Children.Add(uiElement);
// we removed the previous root page, and the new root page is the one being presented
// at this time there's only 1 page now on the stack (the navigationpage with root)
// we need to update the platform to set this root page as the visible again
bool updateRoot = Element.CurrentPage == first && _isRemoving;
if (updateRoot)
{
platform.SetCurrent(Element, false);
}
}
public static IVisualElementRenderer GetRenderer(VisualElement view)
{
return(Platform.CreateRenderer(view));
}